植物乳杆菌LP1103降低小鼠血清胆固醇作用机理的探讨

从泡菜中分离筛选到1株降胆固醇能力为42.5%的乳酸菌LP1003,经初步鉴定为植物乳杆菌。用其菌液及该乳酸菌发酵奶喂养高脂模型小鼠,研究其对胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)、总胆酸(TBA)以及体质量和肝质量的影响。结果发现,4周后,与高脂模型组相比,实验组小鼠血清中TC、TG和TBA含量明显下降(p<0.05);粪便中TC、TBA含量升高,各组间小鼠的HDL-C、体质量、肝质量/体质量无显著差异。通过计算得到实验组小鼠患高血脂症的风险指数和动脉硬化指数均低于对照水平。     

发酵乳杆菌SM-7的筛选及对小鼠降胆固醇作用

筛选1 株具有高效降胆固醇活性的乳酸菌菌株并研究其降胆固醇的特性。采用分离自新疆酸马奶的10 株乳酸菌,通过益生活性的测定以及降胆固醇实验筛选得到1 株具有高效降胆固醇的益生菌株SM-7,经过鉴定为发酵乳杆菌。该菌株在液体培养基中的胆固醇脱除率为66.82%,用该菌液饲喂小鼠4 周,研究其对小鼠血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)以及体质量和肝、肾质量的影响。结果显示,实验组小鼠的血清TC、TG、LDL-C 含量均显著低于高脂模型组(P ＜ 0.01),而HDL-C 含量没有显著差异(P ＞ 0.05)。这表明发酵乳杆菌SM-7 对实验性高脂血症小鼠血清有显著的降胆固醇作用。     

降胆固醇乳酸菌的筛选及其降胆固醇活性研究

为了得到一株高效降胆固醇的乳酸菌并研究其降胆固醇的特性,本研究通过体外筛选得到一株降胆固醇能力为41.87%的乳酸乳球菌乳亚种LQ-12,并用该乳酸菌发酵酸奶饲喂高脂模型大鼠,研究其对血清总胆固醇(TC)、血清甘油三酯(TG)、血清高密度脂蛋白(HDL-C)、血清总胆酸(TBA)、肝脏总胆固醇(TC)、粪便总胆固醇(TC)、粪便总胆酸(TBA)以及体重和肝、肾、脾重量的影响。结果发现28d后,与高脂模型组相比,实验组大鼠血清中TC、TG和TBA含量明显下降(p<0.05);粪便中TC含量升高,而TBA含量降低;肝重/体重显著降低。各组间大鼠的HDL-C、体重、肾重/体重、脾重/体重无显著差异。     

降胆固醇乳酸菌的筛选及其降胆固醇活性研究

为了得到一株高效降胆固醇的乳酸菌并研究其降胆固醇的特性,本研究通过体外筛选得到一株降胆固醇能力为41.87%的乳酸乳球菌乳亚种Q,并用该乳酸菌发酵酸奶饲喂高脂模型大鼠,研究其对血清总胆固醇(TC)、血清甘油三酯(TG)、血清高密度脂蛋白(HDL-C)、血清总胆酸(TBA)、肝脏总胆固醇(TC)、粪便总胆固醇(TC)、粪便总胆酸(TBA)以及体重和肝、肾、脾重量的影响.结果发现28d后,实验组大鼠血清中TC、TG、TBA和肝脏中TC含量明显下降(P＜0.05),粪便中TC和TBA含量也降低.各组间大鼠的HDL-C、体重、肝重/体重、肾重/体重、脾重/体重无显著差异.     

植物乳杆菌发酵乳对小鼠降胆固醇作用

目的:利用从泡菜中分离的一株植物乳杆菌制备发酵乳并研究其降血脂功能。方法:采用该植物乳杆菌混合市售发酵剂制备发酵乳,发酵剂与植物乳杆菌接种量分别为0.05%(V/V)和2%(V/V),发酵温度为37 ℃,时间14 h。采用高血脂模型小鼠研究发酵乳的降血脂功能,将30只小鼠随机分成正常组、对照组和发酵乳组3 组,正常组喂基础饲料,对照组和发酵乳组喂高脂饲料,正常组和对照组灌胃生理盐水,发酵乳组灌胃发酵乳,正常组和对照组小鼠饲养14 d后采血,检测血清中的TC、TG含量,小鼠饲养28 d后,测定血清中的TC、TG、LDL-C、HDL-C含量以及肝脏中的TC、TG含量。结果表明:所得发酵乳具有清香、口感好的特点;动物实验显示,小鼠饲养14 d后,与正常组相比,对照组血清中的TC、TG含量显著升高(p<0.05),表明高脂模型诱导成功;28 d后,发酵组小鼠血清和肝脏中的总胆固醇(TC)、甘油三酯(TG)与对照组相比显著降低(p<0.05)。微生物检验结果表明,肝脏中没有发现乳酸菌,发酵乳在小鼠体内不会发生肝肠易位现象。结论:含有植物乳杆菌的发酵乳对高脂小鼠具有一定的降血脂功能,可以使小鼠血清和肝脏中的总胆固醇(TC)、甘油三酯(TG)显著降低(p<0.05)。     

干酪乳杆菌KM-16的筛选及其降胆固醇活性研究

从西藏传统发酵乳(西藏灵菇)中分离筛选到1株高效降胆固醇乳酸菌KM-16。应用VITEK-32全自动微生物分析系统鉴定该菌为干酪乳杆菌(Lactobacilluscasei)。在液体培养基中KM-16乳酸菌对降胆固醇达51.8%。用KM-166灌胃高脂血症模型小鼠研究其对血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)的影响。结果表明,灌胃14d后,实验组小鼠血清中TC、TG浓度较对照组显著降低(P<0.01),同时HDL-C浓度有所增加,动脉硬化指数(AI)低于对照的水平。     

西藏干酪乳酸菌降胆固醇特性研究

从西藏传统发酵乳(西藏灵菇)中分离筛选到1株高效降胆固醇乳酸菌KM-16。应用VITEK-32全自动微生物分析系统鉴定该菌为干酪乳杆菌(Lactobacillus casei)。在液体培养基中KM-16乳酸菌对降胆固醇达51.8%。用KM-166灌胃高脂血症模型小鼠研究其对血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)的影响。结果表明灌胃14d后,实验组小鼠血清中TC、TG浓度较对照组显著降低(p<0.01),同时HDL-C浓度有所增加,动脉硬化指数(AI)低于对照的水平。     

添加植物乳杆菌的低脂干酪降胆固醇作用

为研究益生菌在干酪中应用的降胆固醇活性,以菌株胆固醇降解率、胆盐水解酶活力及模拟胃肠道耐受性为评价指标,筛选出具有降胆固醇活性的益生菌,并添加到低脂干酪(脂肪含量为1.0%)中,灌胃小鼠35 d,测定小鼠血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)含量、动脉硬化指数(AI)及肝脏、粪便中TC、TG含量。结果表明,植物乳杆菌KLDS 1.0320降胆固醇特性优于其他菌株,胆固醇降解率达到63.72%,模拟胃肠道消化后存活率为82.21%,胆盐水解酶活力为0.71 U/mL。与高脂模型组相比,灌胃添加植物乳杆菌KLDS 1.0320干酪小鼠的TC、TG、LDL-C及AI分别下降21.23%、19.30%、31.73%和35.05%,肝脏中TC、TG显著降低,粪便中TC、TG显著升高(p<0.05)。实验获得了1株具有降胆固醇能力的植物乳杆菌KLDS 1.0320,以干酪为载体在动物体内仍具有降低血清胆固醇的作用,说明其具有应用于干酪发挥降胆固醇活性的潜力。     

植物乳杆菌K25发酵乳降低小鼠血清胆固醇的作用研究

评价添加西藏灵菇源植物乳杆菌K25的发酵乳对饲喂高脂饲料小鼠降胆固醇的作用。结果表明:含植物乳杆菌K25的发酵乳能显著降低高脂模型小鼠血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)以及动脉粥样硬化指数(AI)的水平;对血清高密度脂蛋白胆固醇(HDL-C)有显著地升高作用;对血清甘油三酯(TG)水平无显著影响;饲喂含植物乳杆菌K25发酵乳的小鼠,其粪便中乳酸杆菌数水平比对照组明显增加,而大肠杆菌数无显著差异。因此,植物乳杆菌K25发酵乳具有降低血清胆固醇功效,并能增加肠道内乳酸杆菌的数量。     

自然发酵豆酱中降胆固醇乳酸菌的筛选鉴定及对大鼠血清胆固醇的影响

采用不同培养基从分离自自然发酵豆酱样品中的285株乳酸菌种中分离筛选出3株能够耐受人工胃肠环境,具有降胆固醇作用的乳酸菌,编号分别为DQ17-2、DD1-1、KY1-1,对胆固醇的去除率分别为34. 56%、27. 12%和29. 20%,最后通过形态学观察、生理生化试验、16S r DNA序列鉴定法确定3株乳酸菌均为植物乳杆菌。将菌株DQ17-2重新命名为植物乳杆菌WW(L. plantarum WW),为了进一步验证其在体内的降胆固醇作用,将32只5周龄雄性SD大鼠随机分为4组:普通对照组(A)、高脂模型组(B)、脱脂乳对照组(C)、菌液干预组(D)。饲喂12周后,采血,测定血清总胆固醇(totalcholesterol,TC)、高密度脂蛋白胆固醇(highdensity lipoprotein-cholesterol,HDL-C)、低密度脂蛋白胆固醇(lowdensity lipoprotein-cholesterol,LDL-C)、甘油三酯(triglyceride,TG)含量。结果表明,饲喂12周后成功构建高脂模型,与B组和C组相比,D组血清TC、TG、LDL-C含量明显降低(P 0. 05),HDL-C含量明显升高(P 0. 05)。该实验筛选出一株在体内外均具有降胆固醇作用的L. plantarum WW,为今后降胆固醇产品的研发提供原料与依据。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.